Fix path components parsing

[fpseverino]

This PR closes #115

• Revert path component parsing to a custom URL.pathComponents based one, instead of the one offered by RoutingKit
• Adopt VaporTesting

This PR fixes a bug that makes almost all services (Google, Auth0, Facebook, etc.) unusable, but it also opens #43 again for said services.

[codecov]

Codecov Report

Attention: Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.

Project coverage is 82.37%. Comparing base (81e0b74) to head (3f7c4f2).

Files with missing lines	Patch %	Lines
Sources/ImperialCore/String+pathSegments.swift	90.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #116      +/-   ##
==========================================
+ Coverage   82.27%   82.37%   +0.09%     
==========================================
  Files          58       59       +1     
  Lines         790      800      +10     
==========================================
+ Hits          650      659       +9     
- Misses        140      141       +1     

Files with missing lines	Coverage Δ
Sources/ImperialCore/FederatedServiceRouter.swift	75.00% <100.00%> (ø)
Sources/ImperialGoogle/JWT/GoogleJWTRouter.swift	82.05% <100.00%> (ø)
Sources/ImperialGoogle/Standard/GoogleRouter.swift	97.05% <ø> (ø)
Sources/ImperialCore/String+pathSegments.swift	90.00% <90.00%> (ø)